Many concrete walls are foamed with apertures to provide space through which pipes, wiring, ducts, or other conduits may pass. Traditionally, these apertures have been created by positioning some type of aperture-forming device, such as a tube or other hollow object, in a form before introducing the concrete. One or both ends of the tubular opening on the aperture-forming devices are usually covered by a cap, seal, or other type of membrane to prevent concrete from entering the voids created by these devices.
Traditionally, these aperture-forming devices were held in place within the concrete form by securing the aperture-forming devices directly to the form. Such a method, however, is undesirable as it is labor-intensive and can damage the form such that it cannot be re-used. Other techniques utilize a grid system, where two grid sections are snapped together to encircle the entire diameter of the aperture-forming device. One drawback of these grid systems is that they cannot be installed in the concrete form prior to installation of the aperture-forming devices because the grid system is designed to snap-fit around the aperture-forming device before the next section is installed. Moreover, these grid systems typically require two modular grid components to secure one aperture-forming device. Also, because the grid sections are typically formed of rigid structures, it is difficult, if not impossible, to insert aperture-forming devices after the installation of the grid system.